Entomology for beginners. Entomology is the study of insects. This page provides some basic information on insects. First we look at the anatomy of adult insects, and then we will see a short story about the metamorphosis of insects. Insect anatomy.
The range rule tells us that the standard deviation of a sample is approximately equal to one fourth of the range of the data. In other words s = (Maximum â Minimum)/4. This is a very straightforward formula to use, and should only be used as a very rough estimate of the standard deviation.
The variance (Ï 2), is defined as the sum of the squared distances of each term in the distribution from the mean (Î¼), divided by the number of terms in the distribution (N). There's a more efficient way to calculate the standard deviation for a group of numbers, shown in the following equation: You take the sum of the squares of the terms in the distribution, and divide by the number of terms in the distribution (N). From this, you subtract the square of the mean (Î¼2). It's a lot less work to calculate the standard deviation this way.